As already well known, multifilament synthetic yarns are often utilized in the production of conventional wigs for women, or for dolls, such yarns being previously treated to impart a given wavy form thereto. Such purpose is attained in practice by having the yarns wound in a tight, continuous spiral, which is then transferred into a heater, whereby to set the crimping.
For such treatment, recourse is presently made to machines wherein the yarn is eccentrically led through a mandrel, which is revolvingly driven about a supporting cyclindrical element, coaxially thereto, whereby to form a continuous spiral winding thereon. While said mandrel is turning, the supporting element should not revolve about its own axis, to prevent a rotation of spiral yarn winding which is being formed.
On the other hand a securing of said supporting element to the machine bed would be impracticable, since the yarn which is being wound is to be passed therethrough.